A shielded coupler, such as an electrical connector, is provided with a colloidal form of gel fill that includes granular powdered particles of electromagnetic shielding material, such as Parites and ferrites, in sufficient density to absorb radio frequency energy. The filling of colloidal gel maintains the shielding material in the form of small discrete particles in suspension that provides a re-enterable electrical connection.
Various gel filled connectors have been advanced, including those which are used in the communications field for protecting the contacts in a communication line socket and plug from the environment. The gels can be selected to have various degrees of viscosity, and will move away from the contacts as a plug is inserted into a socket, but also generally will have enough body to reseal and cover the contacts when a plug is removed.
The gels that are used range across quite a wide range of viscosity. A gel that will work for the present invention is a polyurethane gel sold by CasChem, Inc., 40 Avenue A, Bayonne, N.J. 07002 under the trademark QURE as System 172 X-Linked Polyurethane Gel. It is a combination of Vorite 3035 and Polycin 3540, both of which are products sold under those registered trademarks. The colloidal form of gel is of a medium viscosity, amber in color with a high cone penetration value. The colloidal gel is such that it can be pressed around or penetrated by fixtures intended to be protected from environmental exposure and it has a high level of tack so as to bond to itself or to contacts and surfaces of a connector. The colloidal gel will separate to permit some component, such as a plug, to be inserted into the connector. Gels without a shielding material filling are used as a sealing compound for various electrical devices and cables.
A gel filled electrical connector that utilizes an elastic diaphragm for urging the gel into place when a plug is removed from a socket is shown in U.S. Pat. No. 5,246,383, by way of example.
A shielding and filtering additive, sold under the trademark "Parite" is part of a family of fired body materials manufactured by Steward Incorporated, 12 E. 36th Street, Chattanooga, Tenn. The material is a substantially homogenous mixture of manganese oxide and iron oxide powder. The use of Parite particles in other electrical devices, such as noise suppressors, is disclosed in U.S. Pat. No. 5,500,629. Some uses are described under the heading "objectives" at column 4, lines 27-43 of U.S. Pat. No. 5,500,629. Ferrites include a mix of oxides of manganese and iron, that can be modified by oxides of zinc, nickel and other metals. Ferrites are powdered or disintegrated ferrous-based materials.